Sinter‐Resistant Platinum Catalyst Supported by Metal–Organic Framework

Abstract

Single atoms and few-atom clusters of platinum are uniformly installed on the zirconia nodes of a metal-organic framework (MOF) NU-1000 via targeted vapor-phase synthesis. The catalytic Pt clusters, site-isolated by organic linkers, are shown to exhibit high catalytic activity for ethylene hydrogenation while exhibiting resistance to sintering up to 200 °C. In situ IR spectroscopy reveals the presence of both single atoms and few-atom clusters that depend upon synthesis conditions. Operando X-ray absorption spectroscopy and X-ray pair distribution analyses reveal unique changes in chemical bonding environment and cluster size stability while on stream. Density functional theory calculations elucidate a favorable reaction pathway for ethylene hydrogenation with the novel catalyst. These results provide evidence that atomic layer deposition (ALD) in MOFs is a versatile approach to the rational synthesis of size-selected clusters, including noble metals, on a high surface area support.

Designing Nanoparticles and Nanoalloys for Gas-Phase Catalysis with Controlled Surface Reactivity Using Colloidal Synthesis and Atomic Layer Deposition

“…Kim and co-workers [238] applied ALD as a means to synthesize well-defined Pt nanoclusters (<1 nm) on NU-1000, a metal-organic framework (MOF), for their application in ethylene hydrogenation. Their choice of support was motivated by its high surface area, thermal and chemical stability, the presence of -OH and -OH 2 functionalities within the mesoporous (~3 nm) channels-which makes it ideal for ALD-and the space-constraining effect of the framework's organic linker components-which mitigates metal atom migration.…”

Particle atomic layer deposition

“…However, supported metal catalysts deactivate at high temperatures when these metal particles sinter to form larger particles. Particle ALD is used to reduce sintering (Feng et al 2011 ; Liang et al 2011 ; Lu et al 2012 ; Kim et al 2018 ; Phaahlamohlaka et al 2018 ).…”

Understanding the CO Oxidation on Pt Nanoparticles Supported on MOFs by Operando XPS

“…size and shape), chemical state and local environment of MNPs in MOFs, most of the studies have focused on the pre and post reaction characterisation of catalysts, providing snapshots only of their properties. Moreover, experimental observation of the working state of MNPs in MOFs in comparison with conventional supports such as metal oxides is still largely lacking . Herein, we report the first comparative study of platinum (Pt) NPs supported on UiO‐67 and zirconia (ZrO 2 ) using operando near‐ambient pressure X‐ray photoelectron spectroscopy (NAP‐XPS) with simultaneous mass spectrometry to elucidate the role of MOFs as catalyst supports.…”